959 resultados para McCarthy, Thomas
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We report the results of a multimessenger search for coincident signals from the LIGO and Virgo gravitational-wave observatories and the partially completed IceCube high-energy neutrino detector, including periods of joint operation between 2007-2010. These include parts of the 2005-2007 run and the 2009-2010 run for LIGO-Virgo, and IceCube's observation periods with 22, 59 and 79 strings. We find no significant coincident events, and use the search results to derive upper limits on the rate of joint sources for a range of source emission parameters. For the optimistic assumption of gravitational-wave emission energy of 10(-2) M(circle dot)c(2) at similar to 150 Hz with similar to 60 ms duration, and high-energy neutrino emission of 1051 erg comparable to the isotropic gamma-ray energy of gamma-ray bursts, we limit the source rate below 1.6 x 10(-2) Mpc(-3) yr(-1). We also examine how combining information from gravitational waves and neutrinos will aid discovery in the advanced gravitational-wave detector era.
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Gravitational waves from a variety of sources are predicted to superpose to create a stochastic background. This background is expected to contain unique information from throughout the history of the Universe that is unavailable through standard electromagnetic observations, making its study of fundamental importance to understanding the evolution of the Universe. We carry out a search for the stochastic background with the latest data from the LIGO and Virgo detectors. Consistent with predictions from most stochastic gravitational-wave background models, the data display no evidence of a stochastic gravitational-wave signal. Assuming a gravitational-wave spectrum of Omega(GW)(f) = Omega(alpha)(f/f(ref))(alpha), we place 95% confidence level upper limits on the energy density of the background in each of four frequency bands spanning 41.5-1726 Hz. In the frequency band of 41.5-169.25 Hz for a spectral index of alpha = 0, we constrain the energy density of the stochastic background to be Omega(GW)(f) < 5.6 x 10(-6). For the 600-1000 Hz band, Omega(GW)(f) < 0.14(f/900 Hz)(3), a factor of 2.5 lower than the best previously reported upper limits. We find Omega(GW)(f) < 1.8 x 10(-4) using a spectral index of zero for 170-600 Hz and Omega(GW)(f) < 1.0(f/1300 Hz)(3) for 1000-1726 Hz, bands in which no previous direct limits have been placed. The limits in these four bands are the lowest direct measurements to date on the stochastic background. We discuss the implications of these results in light of the recent claim by the BICEP2 experiment of the possible evidence for inflationary gravitational waves.
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This paper analyzes the character Bigger Thomas Native Son’s American novel published in 1940 by African-American author Richard Wright. Through this character we try to study more the post-slavery racial issue in a country where racial segregation was legally sustained and how this issue was reflected in society and identity formation of their native sons African-American
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In this paper we present the results of a coherent narrow-band search for continuous gravitational-wave signals from the Crab and Vela pulsars conducted on Virgo VSR4 data. In order to take into account a possible small mismatch between the gravitational-wave frequency and two times the star rotation frequency, inferred from measurement of the electromagnetic pulse rate, a range of 0.02 Hz around two times the star rotational frequency has been searched for both the pulsars. No evidence for a signal has been found and 95% confidence level upper limits have been computed assuming both that polarization parameters are completely unknown and that they are known with some uncertainty, as derived from x-ray observations of the pulsar wind torii. For Vela the upper limits are comparable to the spin-down limit, computed assuming that all the observed spin-down is due to the emission of gravitational waves. For Crab the upper limits are about a factor of 2 below the spin-down limit, and represent a significant improvement with respect to past analysis. This is the first time the spin-down limit is significantly overcome in a narrow-band search.
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We present results of a search for continuously emitted gravitational radiation, directed at the brightest low-mass x-ray binary, Scorpius X-1. Our semicoherent analysis covers 10 days of LIGO S5 data ranging from 50-550 Hz, and performs an incoherent sum of coherent F-statistic power distributed amongst frequency-modulated orbital sidebands. All candidates not removed at the veto stage were found to be consistent with noise at a 1% false alarm rate. We present Bayesian 95% confidence upper limits on gravitational-wave strain amplitude using two different prior distributions: a standard one, with no a priori assumptions about the orientation of Scorpius X-1; and an angle-restricted one, using a prior derived from electromagnetic observations. Median strain upper limits of 1.3 x 10(-24) and 8 x 10(-25) are reported at 150 Hz for the standard and angle-restricted searches respectively. This proof-of-principle analysis was limited to a short observation time by unknown effects of accretion on the intrinsic spin frequency of the neutron star, but improves upon previous upper limits by factors of similar to 1.4 for the standard, and 2.3 for the angle-restricted search at the sensitive region of the detector.
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The Advanced LIGO gravitational wave detectors are second-generation instruments designed and built for the two LIGO observatories in Hanford, WA and Livingston, LA, USA. The two instruments are identical in design, and are specialized versions of a Michelson interferometer with 4 km long arms. As in Initial LIGO, Fabry-Perot cavities are used in the arms to increase the interaction time with a gravitational wave, and power recycling is used to increase the effective laser power. Signal recycling has been added in Advanced LIGO to improve the frequency response. In the most sensitive frequency region around 100 Hz, the design strain sensitivity is a factor of 10 better than Initial LIGO. In addition, the low frequency end of the sensitivity band is moved from 40 Hz down to 10 Hz. All interferometer components have been replaced with improved technologies to achieve this sensitivity gain. Much better seismic isolation and test mass suspensions are responsible for the gains at lower frequencies. Higher laser power, larger test masses and improved mirror coatings lead to the improved sensitivity at mid and high frequencies. Data collecting runs with these new instruments are planned to begin in mid-2015.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The Martha Thomas Fitzgerald Papers consist of biographical data, correspondence, minutes, newspaper clippings, memoranda, reports, and photographs (of particular interest are the many photographs of rural S.C. school houses in the 1920s). The collection pertains to Mrs. Fitzgerald’s work with the South Carolina Department of Education, the South Carolina House of Representatives, and her work with various civic organizations such as the Altrusa Club, the League of Women Voters, the Daughters of American Colonists, United Daughters of the Confederacy (UDC), Business and Professional Women’s Club (BPW), Delta Kappa Gamma, South Carolina Vocational Rehabilitation, and the Salvation Army. There is also information on the Status of Women Commission Council on Aging, agriculture, Queens College, University of South Carolina, Winthrop University, Columbia University, public health, South Carolina history, City of Columbia, South Carolina, and Richland County, South Carolina. Correspondents include Strom Thurmond and three letters from John F. Kennedy when he was senator. Mrs. Fitzgerald was the first woman elected to the South Carolina House of Representatives in a general election.
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The Thomas Belue Collection consists of the diary of Thomas Belue of Union County, South Carolina. He enrolled as a private in the Confederate Army in Co. F, Captain C.W. Boyd’s , 15th SCV. The diary covers August, 1861 to September, 1863, and May 1864. Belue describes battles fought in South Carolina, Georgia,Tennessee, and Virginia, mileage covered, camp life and events that occurred during his time in the army. The collection also includes biographical information, genealogical information, a partial transcript of the diary, and copies of Belue’s military records. In addition there is a tintype in a case of Belue in his uniform, two copies of the tintype, and photographs of his gravestone at Gilead Baptist Church Cemetery in Union County, South Carolina.
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The Thomas Spratt Memoir consists of a typescript account titled Recollections of the Spratt Family, detailing the history of the Spratt family of York County, South Carolina from the arrival in America of Thomas Spratt from County Down, Ireland, in 1740 to 1876.
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Thomas Smithwick Gettys (1912-2003) was a lawyer and U.S. Representative for the Fifth Congressional District of South Carolina. The Thomas Smithwick Gettys Papers consist of reports, resolutions, correspondence, news releases, government publications, and newspaper clippings, relating to Getty’s efforts to enlarge and develop the Cowpens Battlefield Site of Cherokee County, South Carolina. Correspondents include Ernest Hollings, Donald Russell, John P. Saylor, W.S. Stuckey, Jr., Roy A. Taylor, Mark W. Clark, Wayne Aspinall, and Stewart Udall.
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The Thomas Jefferson Johnston Papers consists of the Civil War diary of Thomas Jefferson Johnston (1837-1894) from 1861 to August 7, 1864. Also included is a transcription of the journal as well as contextual notes of what was occurring during the war at large by Robert James Johnston (1945-) (great grandson of Thomas Jefferson Johnston) in 1992.
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Although Lewis and Clark literature has proliferated in the last decade, few works have added scholarly discourse to this field of study. The highly focused Venereal Disease and the Lewis and Clark Expedition, however, will likely stand out on the Lewis and Clark bookshelf as an important contribution.
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Clyomys Thomas, 1916 is a semifossorial rodent genus of spiny rats represented by only one species, C. laticeps, which inhabits the tropical savannas and grasslands of central Brazil and eastern Paraguay. Here we describe a new karyotype of C. laticeps found in populations of Emas National Park, Goias state, Brazil. The four analyzed specimens had a diploid number (2n) of 32 and a fundamental autosome number (FN) of 54. Cytogenetic data include conventional staining, CBG and GTG-banding. The karyotype presents 12 meta/submetacentric pairs (1 to 12) and 3 pairs of acrocentrics (13 to 15) with gradual decrease in size. The X chromosome is a medium submetacentric and the Y is a medium acrocentric. The semifossorial habits together with habitat specificity could have contributed to the karyological variations found on this genus.